Since Krell 302e & Cary SPL-05 have (gain/imp issues) what tube pre is best w/ the krell?

Looking SS enhanced sounstage,bass slam plus the warmth of tubes.

I would actually look at the Krell 202 or 222 preamps (even an older Krell KAV-280p is nice, but doesn't have the power supply of the 202/22).  The Krell's bipolar Class A gain circuits give you a nice sweet sound but still have the slam/punch/immediacy.  I would avoid the Krell Phantom preamp as I think they are overpriced and there's nothing much in them (even KAV-280p is better in my opinion).

You could look at some of the Pass Labs preamps.  They are Class A and use JFET/MOSFET gain circuits instead of bipolar.  This may give you more of a richness in the sound (not that Krell would be lacking warmth), but keep in mind that not all FET circuits are created equal.  I have not heard Pass Labs, so I could not comment.

Eric is a fan of Ayre, but I have no idea what that sounds like.

Thank you...Just spoke to some people about Pruma-Luna Dialog pre.
Or Prima-Luna pre and power amp.  Just not sure of how that would sound, and how they would drive Celestion A3 speakers, w/ are very power hungry.
BAT tube preamp with BAT ss amp. Big powerful sound i think your looking for.  
What gain/impedance issue? Impedance looks fine, the output impedance of the SLP-05 is 400 ohms, while the input impedance of the 302e is 100Kohm SE and 200Kohm balanced. No issue at all there.
The Cary gain of 17 dB single ended and 24 dB balanced is a tad on the high side balanced, it still should work fine. 
You can certainly find preamps with less gain, though they will have different sonic signature from the Cary as well.

I would think that you would be better suited by how the preamp/amp sound together then by worrying about how they look next to each other on a spec sheet. I understand impedance matching, to a point, that is no concern in your case. Gain can be adjusted by attenuators, like those available from Rothwell.